a)

\(\dfrac{48}{92}=\dfrac{48:4}{92:4}=\dfrac{12}{23}\)
\(\dfrac{36}{69}=\dfrac{36:3}{69:3}=\dfrac{12}{23}\)
Ta có: 
Mẫu số chung 2 phân số: 23
Vì \(12=12\) nên \(\dfrac{12}{23}=\dfrac{12}{23}\)
Vậy \(\dfrac{48}{92}=\dfrac{36}{69}\)

b)

\(\dfrac{3}{5}+\dfrac{4}{7}+\dfrac{7}{8}=\dfrac{573}{280}\)

Ta có: 
Mẫu số chung 2 phân số: 280
\(\dfrac{3}{1}=\dfrac{3*280}{1*280}=\dfrac{840}{280}\)
Vì \(573< 840\) nên \(\dfrac{573}{280}< \dfrac{840}{280}\)
Vậy \(\dfrac{573}{280}< \dfrac{3}{1}\)

c)
Ta có: 
Mẫu số chung 2 phân số: 10
\(\dfrac{2}{5}=\dfrac{2*2}{5*2}=\dfrac{4}{10}\)
Vì \(1< 4\) nên\(\dfrac{1}{10}< \dfrac{4}{10}\)
Vậy \(\dfrac{1}{10}< \dfrac{2}{5}\)

d)
\(\dfrac{4}{10}=\dfrac{4:2}{10:2}=\dfrac{2}{5}\)
Ta có: 
Mẫu số chung 2 phân số: 5
Vì \(2=2\) nên \(\dfrac{2}{5}=\dfrac{2}{5}\)
Vậy \(\dfrac{4}{10}=\dfrac{2}{5}\)

Hãy quy đồng hộ mình và đánh dấu nha 

\(A=\frac{1\cdot2+2\cdot4+3\cdot6+4\cdot8+5\cdot10}{3\cdot4+6\cdot8+9\cdot12+12\cdot16+15\cdot20}\)

\(=>A=\frac{1\cdot2+4\cdot1\cdot2+9\cdot1\cdot2+16\cdot1\cdot2+25\cdot1\cdot2}{3\cdot4+4\cdot3\cdot4+9\cdot3\cdot4+16\cdot3\cdot4+25\cdot3\cdot4}\)

\(=>A=\frac{\left(1+4+9+16+25\right)\cdot1\cdot2}{\left(1+4+9+16+25\right)\cdot3\cdot4}=\frac{1}{6}=\frac{111111}{666666}\)

Mà \(\frac{111111}{666666}< \frac{111111}{666665}\)

\(=>A< B\)

A

\(\frac{3}{4}=\frac{15}{20}\)    \(\frac{4}{5}=\frac{16}{20}\)

\(\Rightarrow\frac{3}{4}< \frac{4}{5}\)

a) 3/4 < 4/5

b) 5/6 < 7/8

c) 2/5 > 3/10

Chúc bạn học tốt.

😁😁😁

Cảm ơn mấy bạn nha!

A)\(5^3và3^5\)

\(5^3=125;3^5=243\)

Vì\(125< 243\Rightarrow5^3< 3^5\)

B)\(4^3va3^4\)

\(4^3=64;3^4=81\)

Vì\(64< 81\Rightarrow4^3< 3^4\)

C)\(2^4va8^2\)

\(2^4=\left(2^2\right)^2=4^2\)

Vì\(4^2< 8^2\Rightarrow2^4< 8^2\)

câu c thì 2/5 lớn hơn 3/10 

\(\frac{3}{4}\)và\(\frac{4}{5}\)

Ta có :

\(\frac{3}{4}=\frac{15}{20};\frac{4}{5}=\frac{16}{20}\)

Vậy\(\frac{15}{20}< \frac{16}{20}\)kết luận\(\frac{3}{4}< \frac{4}{5}\)

\(\frac{5}{6}\)và\(\frac{7}{8}\)

Ta có :
\(\frac{5}{6}=\frac{40}{48};\frac{7}{8}=\frac{42}{48}\)

Vậy\(\frac{40}{48}< \frac{42}{48}\)kết luận\(\frac{5}{6}< \frac{7}{8}\)

\(\frac{2}{5}\)và\(\frac{3}{10}\)

Ta có :

\(\frac{2}{5}=\frac{4}{10};\)giữ nguyên phân số\(\frac{3}{10}\)

Vậy\(\frac{4}{10}>\frac{3}{10}\)kết luận\(\frac{2}{5}>\frac{3}{10}\)

Alo

a) 

\(\dfrac{6}{12}=\dfrac{6:6}{12:6}=\dfrac{1}{2}\)

\(\Rightarrow\dfrac{1}{2}=\dfrac{1\times2}{2\times2}=\dfrac{2}{4}\)

Mà \(\dfrac{2}{4}< \dfrac{3}{4}\)

Vậy \(\dfrac{6}{12}< \dfrac{3}{4}\).

b)

\(\dfrac{8}{10}=\dfrac{8:2}{10:2}=\dfrac{4}{5}\)

Mà \(\dfrac{2}{5}< \dfrac{4}{5}\)

Vậy \(\dfrac{2}{5}< \dfrac{8}{10}\).

c)

\(\dfrac{40}{35}=\dfrac{40:5}{35:5}=\dfrac{8}{7}\)

Mà \(\dfrac{8}{7}>\dfrac{6}{7}\)

Vậy \(\dfrac{40}{35}>\dfrac{6}{7}\).

d)

\(\dfrac{8}{16}=\dfrac{8:8}{16:8}=\dfrac{1}{2}\)

Mà \(\dfrac{1}{2}< \dfrac{5}{2}\)

Vậy \(\dfrac{8}{16}< \dfrac{5}{2}\).